Elvis, our waiter and entertainer, sauntered over to our table, seemingly excited to serve his only dinner customers. This Elvis looked nothing like the King; his tattooed arms would make the Illustrated Man feel inadequate, and his goatee was right out of Scooby Doo. Elvis (real name: Ron) plays guitar for the Dead Celebrities (voted best punk band by Riverfront Times readers the past two years running). Clearly, he was in his element at Infierno, the funky new Mexican restaurant that recently took up where the Hungry Buddha left off on Washington Avenue downtown.

For a while, rumor had it that after closing Hungry Buddha, restaurateur Blake Brokaw (Tangerine, the Chocolate Bar) aimed to open a Mexican eatery in the same space. Instead, he sold the spot to a former employee, Darlene Warfield, and her husband, Charlie -- his parents own the Bean House Mexican restaurant in south county -- who pursued the late-night Mexican concept themselves.

Though the theme is continents apart from the Hungry Buddha's cheap Asian eats, Infierno perpetuates the bohemian vibe with its spare, rather unfinished look: Mexican crucifixes hanging on mottled yellow walls, Mexican beer labels forming a border around the room, a string of lights and various Mexican trinkets adorning the bar area. Most nights there's punk, post-punk, alt-rock and pop-punk music throbbing from the speakers, which is a draw for the punk, post-punk, alt-rock and pop-punk crowds that pack the place late on weekends to see the bands that Elvis books.

But with his laid-back yet eager manner, Ron (I mean Elvis) could probably make even the most straight-laced, non-pierced, corp-rock listener feel welcome. For that matter, he's also good at recommending dishes -- even if they're not listed on the menu. The basic quesadilla, for instance, that he suggested we have the kitchen fatten up with two cheeses, shredded chicken and black beans.

If I were to look at Infierno's menu with a cool eye, I'd yawn. Nothing remarkable here, just your typical Tex-Mex: tacos, enchiladas, burritos, tamales, tostadas and chimichangas, offered à la carte and priced from $1.75 to $3.50 apiece. All but the tamales come with your choice of fillings: ground or shredded beef, chicken, pork, cheese, vegetables or beans (whole or refried pintos, or black). For a few bucks more ($7 for lunch, $8 for dinner), you can combine any two items and get beans and rice to boot.

The other entrée items seem perfectly suited for late-night noshing, which is appropriate, given that Infierno serves a full menu right up to 3 a.m. on weekends (midnight on weeknights) for hungry, staggering club hoppers. And it's about damn time; I can't remember such a late-night-friendly Mexican establishment since the days of the Naugle's Macho-Combo Burrito. Our table ordered it all, mostly, and found a couple of standouts and some clunkers as well. To dispense with the latter: We loved the earthy, smoky flavor of the chicken and black-bean tortilla soup but balked a bit at its saltiness. A plain black-bean burrito proved too plain -- just plain black beans wrapped up in a plain tortilla. And the dreary ground-beef tamale was devoid of the kind of flavor you can find at any taquería on Cherokee Street.

The grilled steak burrito, however, resurrected our taste buds with chunks of seasoned cooked meat wrapped neatly in a tortilla and then grilled. A flank-steak torta was a tasty Mexican sandwich made with tender and juicy sliced meat, black beans, cheese, tomato and avocado -- though serving it open-faced on hamburger buns seemed odd, almost goofy.

The most expensive items on the menu -- an eight-ounce rib eye, and catfish or grouper prepared either grilled or blackened -- will still set you back only about $8 each. This is standard, cheap Tex-Mex fare, more El Paso than Chihuahua, and the folks at Infierno don't pretend otherwise. You won't encounter anything remotely Nuevo Latino; no duck breast in chipotle-fig sauce. Not even authentic dishes like mole, posole or carnitas. And that's just fine, thank you very much.

Everything is house-made, including the magnificent salsa and superb guacamole: the former chunky and red with a sweet beginning due to roasted red peppers, evolving into a pleasant mouth-filling heat that doesn't overwhelm or incinerate your tongue; the latter simple, chunky and creamy with hints of garlic. A grilled steak kebab special one night hit the spot with two skewers of seasoned beef, rice, beans and a little salad in the middle of the plate -- all for $7.95.

Infierno stocks a full selection of Mexican beers. They also make a decent 'rita for $4.95. For $7, if you're the type, you can upscale to a margarita made with Corazón reposado tequila, Cointreau, fresh lime juice and, oddly, a float of amaretto.

Four desserts are offered. Passing over the Choco Taco (yes, the same ones you get from the ice cream man), we heeded Elvis' advice and went with a churro, and also cinnamon chips with fruit salsa. The churro consisted of thin sheets of pastry filled with cream cheese, rolled and fried; a sprinkling of powdered sugar and cinnamon further sweetened the addictive confection. For the fruit salsa, thawed strawberries and raspberries are puréed and sweetened with honey; into this mixture, you dip deep-fried cinnamon chips. It's as addictive as the spicy version dished out at the beginning of the meal.

Sometime during our multicourse feast, Elvis fetched an out-of-tune guitar, pulled up a chair and asked, "Know any tunes?" One member of our party took him up on the offer, tuned the guitar and proceeded to noodle a blues riff. Impressed, Elvis took back the instrument and launched into a Robin Trower lick.

A waiter who picks out Robin Trower lines in a Tex-Mex joint on Washington Avenue. You've got to appreciate the spunk of a place like that.